Mustard Greens in Zone 9B — Texas

Mustard greens pack a peppery punch that's delicious sautéed, added to soups, or even eaten raw when the leaves are young. Here in Texas, their fast growth and tolerance for cooler weather makes them a rewarding crop for both spring and fall gardens. You get two chances to enjoy them!

Our unpredictable weather can be a challenge, with that Texas heat coming on fast. But with a little planning and attention to timing, you can easily grow mustard greens during our long, 308-day growing season. Don't let those challenges scare you away!

Starting mustard greens indoors gives you a head start, especially for an early spring crop. Sow seeds late December through mid January, about three weeks before you plan to transplant. This is most useful if you want to get a very early start, capitalizing on our early spring.

Use seed trays or small pots filled with a good seed-starting mix. Keep them warm (around 70°F) and provide plenty of light – a grow light works great. Don't forget to water from the bottom to encourage strong root growth!

Transplant your mustard green seedlings outdoors from late January through early March. This gives them a chance to establish before the Texas heat really kicks in.

Harden off your seedlings by gradually exposing them to outdoor conditions for about a week before transplanting. Space them 6-12 inches apart in well-drained soil. Be mindful of any late freezes we sometimes get – have row covers ready to protect them!

Direct sowing mustard greens is a simple and effective method, especially for fall crops. Sow seeds early January through mid October. This gives you a wide window to work with!

Prepare your soil by loosening it and adding compost. Ensure the soil temperature is at least 45°F. Sow seeds about ¼ inch deep, spacing them 6-12 inches apart. Thin seedlings as needed. Keep the soil consistently moist for germination.

Mustard greens need consistent moisture to thrive, but they don't like soggy soil. In our Texas climate, that can be a tricky balance. During the spring and fall growing seasons, aim to water deeply about once or twice a week, depending on rainfall.

Use the "finger test" – stick your finger into the soil about 2 inches deep. If it feels dry, it's time to water. Give them about 1 inch of water per week. Water at the base of the plants to avoid wetting the leaves, which can lead to fungal diseases, especially with our variable humidity.

During the hotter parts of the year, you might need to water more frequently. Wilting leaves are a sign of underwatering, while yellowing leaves can indicate overwatering. A layer of mulch helps retain moisture and regulate soil temperature.

You can expect your first harvest of mustard greens from late February through mid December. That's a long harvest window for Texas gardeners! They typically mature in about 45 days.

Harvest young leaves for a milder flavor. Larger leaves will be spicier. Pick leaves before the plant starts to flower (bolt). Simply snip off the outer leaves, leaving the inner ones to continue growing.

This encourages continuous production throughout the season. As the first frost approaches in early December, harvest any remaining leaves to enjoy. You can also cover the plants to extend the harvest a bit longer if the freeze is light.

Here are some common problems you might encounter with mustard greens in Texas:

Flea Beetles

• What it looks like: Tiny round holes (shot-hole pattern) in leaves. Small dark beetles that jump when disturbed.
• What causes it: Small jumping beetles that feed on leaves of brassicas. Worst damage to young seedlings.
• How to fix/prevent it: Row covers protect seedlings. Delay planting until plants are larger. Kaolin clay coating. Neem oil spray.

Aphids

• What it looks like: Clusters of tiny insects (green, black, or white) on stems and leaf undersides. Sticky honeydew. Curled or distorted growth.
• What causes it: Rapid-reproducing sap-sucking insects. Populations explode in warm weather.
• How to fix/prevent it: Strong water spray knocks them off. Encourage ladybugs. Insecticidal soap. Neem oil.

Cabbage Worms

• What it looks like: Smooth green caterpillars on leaves. Irregular holes. Dark green droppings. White butterflies around plants.
• What causes it: Larvae of white cabbage butterflies. Multiple generations per season.
• How to fix/prevent it: Bt spray is effective. Floating row covers prevent egg laying. Handpick caterpillars.

Bolting in Heat

• What it looks like: Plant sends up a flower stalk. Leaves become tough and bitter.
• What causes it: Extended warm temperatures. Brassicas bolt when days consistently exceed 80°F.
• How to fix/prevent it: Time plantings for cool weather. Choose bolt-resistant varieties. Provide shade. Mulch. Harvest before bolting.

Texas Specific Challenges: The extreme heat, variable humidity, and unpredictable rainfall in Texas can exacerbate these problems. Heat stress makes plants more susceptible to pests and diseases. It also encourages bolting. Consistent monitoring and proactive measures are key to success. And keep an eye out for fire ants when you're working in the garden!

Good companion plants for mustard greens include onions and garlic. They help repel pests like aphids. Beets are also a good choice, as they don't compete for the same nutrients. Dill attracts beneficial insects that prey on pests. Lettuce provides ground cover, helping to keep the soil cool and moist.

Avoid planting mustard greens near strawberries, as they can attract the same pests. Tomatoes are also not ideal companions, as they prefer slightly different soil conditions. Companion planting is especially important in Texas to help your plants thrive in our challenging climate.